Research On Jet Mixing Characteristics Of Supersonic Nozzle

In view of the operational principle of scramjet,injecting fresh air into the solid rocket motor nozzle and burning with gas rich in H2,CO and metal additives was proposed.For the combustion under supersonic condition,the sufficient mixture of fuel and air is one of the key issues to improve the combustion efficiency.Therefore,it is necessary to study it by means of experimental methods and numerical simulation.The experiment was designed to study the jet mixing of supersonic nozzle.The main nozzle and jet nozzle were designed to simulate the nozzle gas and supersonic jet under supersonic flight.The experiment bench,pressure test scheme and gas supply system were designed to carry out the profiling experiment.The structure of the flow field can be clearly observed,including the position of the shock wave,the expansion wave,the compression wave and the stagnation zone.The decrease of the mainstream pressure and the increase of the jet pressure can enhance the jet mixing effect.Based on the experimental results,the numerical simulation model is established.The influence of four parameters such as total jet incident pressure,jet width,jet nozzle position and incident angle on the mixing was further analyzed.Furthemore,the combustion in the jet nozzle was explored.The results show that the total jet pressure and jet width can increase the mixing efficiency and combustion efficiency,and the change of total pressure loss is small.Within a certain range,the jet nozzle position is close to the exit,the mixing efficiency and combustion efficiency will be reduced,the change of total pressure loss is small.While decreasing the incident angle can obviously increase the mixing and combustion efficiency,but the total pressure loss will obviously increase,which need to be considered comprehensively.